>> jernigan: yes, yes. >> faulk: that's right. >> jernigan: i would say we lost $3 million to $4 millionf astronomical figures... ( bell ) half a world away, in a suburb of amsterdam, san francisco's sinking tower came across the radar of petar marinkovic, an engineer who works with the european space agency to track earthquakes. using signals from a satellite 500 miles above the earth, marinkovic measures ground movements around fault lines. in 2016, he happened to be studying the bay area when something caught his eye. this is obviously downtown san francisco. what do the green dots represent? >> marinkovic: green dots represent stable, no displacement or no significant displacement. >> wertheim: stable structures? >> marinkovic: stable structures, yeah. >> wertheim: and the red dots? >> marinkvoc: few red dots means something's going down. something's settling. something's subsiding. something's sinking. >> wertheim: did you know what it was? >> marinkovic: no. >> wertheim: had you heard of millennium tower before this? >> marinkovic: no. >> wertheim: ever been to san francisco? >> ma